Das Partha Pratim, Samanta Sudeshna, Blom Douglas A, Pramanik Srikrishna, Devi P Sujatha, Vogt Thomas, Lee Yongjae
Department of Earth System Sciences, Yonsei University, Seoul 120749, Korea.
Center for High Pressure Science and Technology Advanced Research, Shanghai, China and Micro-Nano System Center, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
Nanoscale. 2020 Aug 28;12(33):17462-17469. doi: 10.1039/d0nr04443a.
A novel strategy of using hydrostatic pressures to synthesize gold-carbon (Au-C) nanohybrid materials is explored. The stable face-centered-cubic (fcc) Au undergoes a structural phase transition to a mixture of primitive orthorhombic and cubic phases as the carbon phase acquires a highly ordered onion-like carbon (OLC) structure which encapsulates the Au nanoparticles, thereby exerting an additional pressure. Increasing the pressure results in a one dimensional (1-D) chain-like structure with the primitive cubic Au nanoparticles contained in an amorphous carbon matrix. The OLC structure allows the formation of quenchable Au nanoparticle phases with the primitive close packing and Au-C hybrids with new mesoscopic structures. Under pressure, we observe the formation of a hybrid material composed of a poorly conducting matrix made of amorphous carbon and conducting OLC-encapsulated Au nanoparticles. The electrical conductivity of this hybrid material under pressure reveals a percolation threshold. We present a new synthesis approach to explore the interplay between atomic and mesoscopic structures and the electrical conductivity of metal hybrid structures.
探索了一种利用静水压力合成金-碳（Au-C）纳米杂化材料的新策略。稳定的面心立方（fcc）金发生结构相变，转变为原始正交相和立方相的混合物，因为碳相获得了高度有序的洋葱状碳（OLC）结构，该结构包裹着金纳米颗粒，从而施加了额外的压力。增加压力会导致一维（1-D）链状结构，原始立方金纳米颗粒包含在非晶碳基质中。OLC结构允许形成具有原始紧密堆积的可淬灭金纳米颗粒相以及具有新介观结构的Au-C杂化物。在压力下，我们观察到由非晶碳制成的低导电基质和OLC包裹的导电金纳米颗粒组成的杂化材料的形成。这种杂化材料在压力下的电导率显示出一个渗流阈值。我们提出了一种新的合成方法，以探索原子和介观结构与金属杂化结构的电导率之间的相互作用。
